Diode Isolation for power FET

[#1]

I am considering using the BT555 Smart Highside Switch.
I have two batteries powering a circuit, and I want to be able to isolate one or the other batteries from the circuit. The stock design would allow current to flow through the intrinsic diode of the FET. I've seen other schematics that solve this by putting two FETs in series, drain-to-drain. Looking at the datasheet, I don't see why this wouldn't work for these smart switches as well.

My thought is to:
Pin2: tie together
Pin4: leave floating
Pin 3 of the first FET goes to Vcc
Pin 1,5 of the first FET goes to pin 1,5 of the second FET
Pin 3 of the second FET goes to load.

Will this work for the BT555?

[User270]

Semiconductor device will probably not work if the GND pin, which has to be connected to the lowest potential of the ciruitry, is floating.

Usually an intrinsic diode is not designed for this use case. Probably the mentioned design with two MOSFET fits better to your needs.

forix